Optical systems typically require a number of optical or photonics modules for operating on light and coupling light to and from optoelectronic devices such as lasers, light emitting diodes, and photodetectors. Such modules typically include optical fibers for transmitting light, and spherical lenses for efficiently coupling light to and from optoelectronic devices and/or optical fibers. Silicon is a favored material for the construction of such modules because of the precision with which supporting indentations and grooves can be formed in silicon for supporting and aligning the various optoelectronic devices, spherical or ball lenses, and optical fibers.
The copending patent application of A. Coucoulas, Ser. No. 679,506, filed Apr. 2, 1991, hereby incorporated herein by reference, described a method for bonding optical fibers and glass ball lenses to aluminum surfaces. Aluminum can easily be coated on silicon surfaces, and, using the Coucoulas method, one can avoid the need for epoxies or other adhesives by using heat and pressure to bond the glass elements to the aluminum coatings.
In the commercial production of devices such as optical and photonics modules, it would be desirable to use machines for bonding optical elements to the substrate. Such elements are very small, typically less than three hundred microns in diameter, they must be located with precision, and it would be desirable to provide a method which is capable of bonding with the requisite precision all of the optical elements to the substrate in one step, rather than requiring sequential bonding of each separate optical element. Besides reducing the cost of making such modules, such a method would tend to improve device quality by reducing the total time during which the substrate is heated, as required for thermo-compression bonding in accordance with the Coucoulas technique. There is therefore a long-felt need for machines and methods for the mass production of optical modules which are of reasonably low cost and which reduce the time and the required operator skill for the production of reliable and high-quality modules.